ARCHERY MECHANICS
	Name:_____________________      Date _____________
 	To be effective at target shooting, you will need to know your bow properties and how to correct for gravity.
	You will need to convert some measurements into a consistent system of units, such as the meter-kilogram-second system. 
	
	TARGET PROPERTIES
		D = Target distance = _________________  yards = _____________________ meters

	BOW PROPERTIES
		My bow description for identification: __________________________________________
		B =brace height: ______________________ inch  = ______________________meters        (from front of bow to string)
	
		W = draw weight at full draw: _____________lbs = _______________________ kg             (used a scale to measure this)
		
	ARROW PROPERTIES 		
		L = arrow length:  _____________________  inch = ______________________ meter         (measure this) 
		M =arrow mass (weight) : _______________ gm  = _______________________kg              (measure this)

	Using these properties we can determine how your target shooting event will go.
            When you draw the bow and release an arrow toward the target, the stored energy in the bow is converted
            into kinetic energy of the arrow, and some heat in the bow. The arrow must be aimed at a point above the
            actual center of the target to compensate for the distance the arrow falls due to gravity during the transit
            time, or time it takes, for the the arrow to reach the target. Notive that we need a consistent set of measuring units.
            We will use the SI system, where distance is in meters, time in seconds,  force in Newtons, and energy in Joules.
            Here is how we determine these:

	STORED ENERGY IN MY BOW:  Stored energy at full draw ( see "Stored Energy" in the Files): 

	E = ( Draw-Wt(kg) x 9.8(m/s/s) x (arrow-length,m - brace-height,m) /2   =  [ W x 9.8 x ( L - B ) / 2]  = ______Newtons
	
	ARROW VELOCITY:       Arrow velocity in flight  (  see "Arrow Velocity" in the Files . From  E = M * V * V/ 2   ) 

            	V= . sqrt ( 2 * E / M )	=   ___________ m / s                                 (Note: sqrt = square root)
  
	TRANSIT TIME TO THE TARGET  ( t = D / V )

		T =transit time  ( target-distance / arrow-velocity ) = D / V  = _____________________ meters/second.	
      
	DISTANCE MY ARROW FALLS DUE TO GRAVITY:  ( Gravity makes the arrow fall at  9.8 m / sec / sec )

		F = 9.8 * T* T / 2  = _____________________ meters
		This is the distance above the target at which you need to aim in order to hit the target.          
            (c) Lee F. Donaghey